I look at recently released Commodore 64 Wizball music source code
Wizball music source code: https://github.com/MartinGalway/C64_music/blob/main/wizball.asm
Debugging notes: https://github.com/martinpiper/DebuggingDetails/blob/main/Wizball%20music%20profile.txt
Wizball videos:
https://youtu.be/qFGLH_ZCqiE
https://youtu.be/e9iU-OoIDwQ
https://youtu.be/uHyIDOCL7JA
The tools video: https://youtu.be/LOUCV-x31U4